I'm unbelievably stuck on this problem. Any help would be appreciated.

Question

Red phosphorous is formed by heating white phosphorous. Calculate the temperature at which the two forms are at equilibrium, given

white P: (heat of formation)= 0.00 kj/mol; standard molar entropy= 41.09 J/mol K
red P: (heat of formation)= -17.6 kj/mol; standard molar entropy = 44.14 J/mol K

When they are in equilibrium, I believe the Gibbs free energy terms H - TS are equal. You could use that relationship to solve for T.

Review the subjects of Gibbs free energy, equilibrium and the Phase rule to verify this assertion.